Pala¨ontol Z (2014) 88:159–166 DOI 10.1007/s12542-013-0193-1
RESEARCH PAPER
Family Dibrachicystidae (Echinodermata: Rhombifera) from the ‘‘Middle’’ Cambrian of the Barrandian area, Czech Republic Oldrˇich Fatka • Michal Szabad
Received: 18 June 2013 / Accepted: 26 June 2013 / Published online: 30 July 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract A slightly crushed but otherwise nearly complete specimen of the recently described rhombiferan echinoderm genus Vizcainoia Zamora and Smith, 2012 is documented from the ‘‘Middle’’ Cambrian Jince Formation of the Prˇ´ıbram–Jince Basin of the Czech Republic. Isolated thecal plates, earlier determined as calyx plates of the eocrinoid Acanthocystites briareus Barrande, 1887 and/or as eocrinoid sp., occurring in diverse levels of the Jince Formation are reassigned to Dibrachicystidae gen. et sp. indet. Similarly, isolated thecal plates collected from the Buchava Formation of the Skryje–Ty´rˇovice Basin could be classified as Dibrachicystidae gen. et sp. indet. Specimens from the Barrandian area are the first records of the family Dibrachicystidae outside of southwestern Europe, of the family otherwise known only from the Languedocian of Montagne Noire of France and from the Caesaraugustian and Languedocian of Iberian Chains of northern Spain. Keywords Cambrian
Vizcainoia Barrandian area ‘‘Middle’’
Kurzfassung Ein leicht angebrochenes, sonst aber fast vollsta¨ndiges Exemplar der Stachelha¨uter-Gattung Vizcainoia Zamora and Smith, 2012, wurde in der mittelkambrischen Jince-Formation des Prˇ´ıbram–Jince Beckens in der Tschechischen Republik gefunden. Isolierte
O. Fatka (&) Faculty of Science, Institute of Geology and Palaeontology, Charles University in Prague, Albertov 6, 128 43 Prague 2, Czech Republic e-mail:
[email protected] M. Szabad Obra´ncu˚ Mı´ru 75, 261 02 Prˇ´ıbram VII, Czech Republic
Kelchplatten aus verschiedenen Lagen der Jince-Formation, welche fru¨her als dem Eocrinoiden Acanthocystites briareus Barrande, 1887 zugeho¨rig klassifiziert wurden, werden nun Dibrachicystidae gen. et sp. indet. zugeordnet. Vergleichbare isolierte Platten aus der Buchava-Formation des Skryje–Ty´rˇovice Beckens geho¨ren ho¨chstwahrscheinlich ebenfalls zu Dibrachicystidae gen. et sp. indet. Die vorliegenden Exemplare aus dem Barrandium sind die ersten Funde dieser Familie außerhalb SW Europas. Bisher war die Familie Dibrachicystidae nur aus dem Languedocian der Montagne Noire in Frankreich und aus dem Caesaraugustian und Languedocian der Iberischen Ketten Nordspaniens bekannt. Schlu¨sselwo¨rter Vizcainoia Barrandium Mittleres Kambrium
Introduction Our knowledge of Cambrian echinoderm Lagersta¨tten has greatly improved in the last two decades. The record of Cambrian echinoderms comprises nearly 200 species classified within eight major groups: (1) helicoplacoids, (2) eocrinoids, (3) edrioasteroids, (4) rhombiferans, (5) cinctans, (6) ctenocystoids, (7) solutes, and (8) stylophorans (Zamora et al. 2013). Recently, the surprising discovery of two-armed echinoderms from the early ‘‘Middle’’ Cambrian of Spain and France supplemented this record (Zamora 2010; Zamora and Smith 2012). The two genera, Dibrachicystis Zamora and Smith, 2012 and Vizcainoia Zamora and Smith, 2012, were assigned to the newly established family Dibrachicystidae. The aim of this contribution is to document the presence of the rhombiferan family Dibrachicystidae from the early
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O. Fatka, M. Szabad b Fig. 1 a Map of the Bohemian Massif showing the Czech Republic and the Cambrian of the Prˇ´ıbram–Jince Basin. b Cambrian of the Prˇ´ıbram–Jince Basin; stars indicate the following fossil sites: Rejkovice ‘‘ve zˇluty´ch’’ locality (1), Vinice slope near Jince locality, outcrop behind the house of Baborsky´ (2); geology modified after Havlı´cˇek (1971). c Cambrian of the Skryje–Ty´rˇovice Basin: old quarry called Buchava in the Buchava Formation (3); geology modified after Masˇek et al. (1997)
‘‘Middle’’ Cambrian sediments of the Jince and Buchava formations of the Barrandian area (Czech Republic).
Geological setting In the Barrandian area, fossiliferous Cambrian rocks have been known in two separate areas: in the large Prˇ´ıbram– Jince Basin and in the smaller Skryje–Ty´rˇovice Basin (Havlı´cˇek 1971; Geyer et al. 2008). Cambrian sediments of both the Jince Formation in the Prˇ´ıbram–Jince Basin and the Buchava Formation in the Skryje–Ty´rˇovice Basin are well known by the occurrence of complete thecae of diverse early echinoderms (e.g., Barrande 1887; Lefebvre and Fatka 2003; Parsley and Prokop 2004; Geyer et al. 2008). The echinoderm fauna established in the Jince Formation includes diverse eocrinoids Acanthocystites Barrande, Akadocrinus Prokop, Lichenoides Barrande, Vyscystis Fatka and Kordule, gen. et sp. nov., the locally common edrioasteroid Stromatocystites Pompeckj, the cinctan Asturicystis Sdzuy, the stylophoran Ceratocystis Jaekel, the ctenocystid Etoctenocystis Fatka and Kordule, and the problematic Cigara Barrande (see Barrande 1887; Ubaghs 1967a, b; Sprinkle 1973; Lefebvre and Fatka 2003; Fatka et al. 2004; Parsley and Prokop 2004; Fatka and Mergl 2009; Nardin et al. 2013). Locally common cinctan Trochocystites Barrande and Trochocystoides Jaekel associated with the eocrinoids Lichenoides Barrande and Luhocrinus Prokop and Fatka, the edrioasteroid Stromatocystites Pompeckj, the stylophoran Ceratocystis Jaekel, and the ctenocystids Etoctenocystis Fatka and Kordule and gen. et sp. nov. represent the echinoderm component of the Buchava Formation (see Pompeckj 1896; Ubaghs 1967a, b, c; Lefebvre and Fatka 2003; Parsley and Prokop 2004). Recently, one articulated specimen of Vizcainoia and tens of isolated thecal plates of dibrachicystids were found at three different outcrops in the Barrandian area. Two of these sites are situated in the Prˇ´ıbram–Jince Basin, namely in the lower third of the Jince Formation in the Litavka River Valley (Figs. 1b, 2a); the third locality with rare findings of thecal plates assigned to dibrachicystids is situated in the middle levels of the Buchava Formation in the
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Family Dibrachicystidae from the ‘‘Middle’’ Cambrian of the Barrandian area
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Fig. 2 a Stratigraphy of the Jince Formation in the Litavka River Valley of the Prˇ´ıbram– Jince Basin; levels containing isolated plates of Dibrachicystidae gen. et sp. indet. and the complete specimen of Vizcainoia sp. Rejkovice ‘‘ve zˇluty´ch’’ locality (1), Vinice slope near Jince locality, outcrop behind the house of Baborsky´ (2); stratigraphy after Fatka and Szabad (2013). b Stratigraphy of the Buchava Formation of the Skryje–Ty´rˇovice Basin; level containing Dibrachicystidae gen. et sp. indet., old quarry called Buchava (3); stratigraphy after Fatka et al. (2011)
Skryje–Ty´rˇovice Basin (Figs. 1c, 2b). At all outcrops, diversified associations of skeletal fauna have been established; a list of taxa is presented in Table 1. Rejkovice ‘‘ve zˇluty´ch’’ locality (Rejkovice ‘‘in yellow’’) Artificial outcrops in purple and grey-green greywackes to fine shales with sandy interlayers exposed along the left side of a narrow field road east of Rejkovice Village (1 in Figs. 1b, 2a); it is locality number 11—Rejkovice ‘‘ve zˇluty´ch’’ in Fatka and Kordule (1992). The diversified fossil association contains common paradoxidid and other trilobites, ichnofossils, very rare agnostids associated with echinoderms, mollusks, and sphenothallids (1 in Table 1).
The Vinice slope near Jince locality, outcrop behind the house of Baborsky´ Rocks above the Litavka River (2 in Figs. 1b, 2a); it is locality number 15 in Fatka and Kordule (1992). The diversified fossil association contains common agnostids, paradoxidid and other trilobites associated with rare brachiopods, ichnofossils, helcionellid mollusks, hyoliths, and different incertae sedis (2 in Table 1). The old quarry called Buchava in the Skryje–Ty´rˇovice Basin Rocks accessible in the old quarry (3 in Figs. 1c, 2b); it is locality number 8 called Slap, Slapsky´ mly´n or Buchava in
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Table 1 Table based on Fatka and Kordule (1992), Fatka et al. (2004, 2012), Kordule (2006), and recently collected material Species/locality
1
Sphenothallus kozaki Fatka et al., 2012
X
Helcionellid mollusks
X
2
Materials and methods X
Hyolithid hyoliths
X X
Brahimorthis sp.
X
3
X
Orthothecid hyoliths Maxilites snajdri Marek, 1972 Luhotreta pompeckji (Sˇlehoferova´, 1980) Glyptacrothele bohemica (Barrande, 1899)
X X
Lingulella sp.
X
X
X
Acrothele quadrilineata Pompeckj, 1896
X
Hadrotreta sp.
X
Bohemiella romingeri (Barrande, 1879) Dawsonia bohemica (Sˇnajdr, 1950) Peronopsis fallax (Linnarsson, 1869) Phalagnostus prantli Sˇnajdr, 1957
rare agnostids, mollusks, and different incertae sedis (3 in Table 1).
The strong weathering of the only nearly complete specimen of Vizcainoia sp. excludes latex casting, and thus documentation by high-resolution optical microscope (Olympus SZX 12) with digital camera (Olympus DP70) was applied (Fig. 3a). This is combined with camera lucida drawing of the external mold (Fig. 3b). The isolated thecal plates are covered by Fe oxides providing a color contrast, and are also photographed without latex casting.
X cf.
X
Systematic paleontology
X
Phylum Echinodermata (Plesion) Rhombifera Family Dibrachicystidae Zamora and Smith, 2012
cf.
Onymagnostus hybridus (Brøgger, 1878) Doryagnostus vinicensis (Sˇnajdr, 1957)
X X
Tomagnostus perrugatus (Gro¨nwall, 1902)
cf.
Peronopsis integra (Beyrich, 1845)
cf.
cf.
Phalacroma bibullatum (Barrande, 1846)
X
X
Phalagnostus nudus (Beyrich, 1845)
Genus Vizcainoia Zamora and Smith, 2012
X
Type species: ‘Eocystites’ languedocianus Ubaghs, 1987; Coulouma Formation, Montagne Noire (France). Solenopleuropsis (Solenopleuropsis) Zone, Lower Languedocian, ‘‘Middle’’ Cambrian; Montagne Noire, France.
X
Vizcainoia sp. Figs. 3, 4d, e
Acadolenus snajdri Fatka and Kordule, 1981 Paradoxides (Acadoparadoxides) sacheri (Barrande, 1852)
X X
Ellipsocephalus hoffi (Schlotheim, 1823)
X
Conocoryphe spp.
X
Ptychopariodes chlupaci Kordule, 2006
X
Material: One more or less complete specimen.
Ptychoparia cf. striata (Emmrich, 1839)
X
Mikaparia milena Kordule, 2006 Novocatharaia havliceki (Sˇnajdr, 1957)
X X
X
Occurrence: Dawsonia bohemica abundance zone, slope called Vinice near Jince, locality number 19 in Fatka and Kordule (1992).
Paradoxides (Eccaparadoxides) pusillus (Barrande, 1846)
X
X
X
Paradoxides (Hydrocephalus) spp.
X
X
X
X
X
X
X
X
Germaropyge spp. Lobocephalina emmrichi (Barrande, 1846)
X
X
X
Skreiaspis spinosus (Jahn, 1896)
X
X
X
Ctenocephalus coronatus (Barrande, 1846)
X
X
X
Asturicystis havliceki Fatka and Kordule, 2001
X
Ceratocystis perneri Jaekel, 1901
X
X
X
Stromatocystites spp.
X
X
X
X
X
Ctenocystid echinoderm
1, Jince Formation, Rejkovice ‘‘ve zˇluty´ch’’ locality (Rejkovice ‘‘in yellow’’); 2, Jince Formation, Vinice slope near Jince locality, outcrop behind the house of Baborsky´; 3, Buchava Formation, old quarry called Buchava
Fatka et al. (2011). The diversified fossil association contains common paradoxidid and other trilobites, associated with brachiopods, hyoliths, ichnofossils, supplemented by
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Description: The only more complete specimen shows a globular to ovate theca composed of irregularly arranged polygonal plates of various sizes. The exterior surface of large thecal plates bears three to seven robust, radial ribs; epispires are absent. Smaller intercalated thecal plates show unornamented outer and inner surface. Position and morphology of periproct are not known. Two large-plated arms arise from the oral region and show spine-like cover plates in proximal and middle parts of both appendages (Fig. 4d, e). At the opposite end of theca, a comparatively long stalk with two distinct regions is preserved. The proximal part of the stalk is composed by about 20 spiked ossicles. However, their poor preservation prevents the possibility to test whether they are arranged in pentameric rings. Six comparatively long cylindrical columnals are assigned to the distal part of the stem; the lowermost of the preserved columnals is slightly moved right; the more distal columnals are missing.
Family Dibrachicystidae from the ‘‘Middle’’ Cambrian of the Barrandian area
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Fig. 3 Nearly complete specimen of Vizcainoia sp. a Photograph of natural mold of nearly complete crushed individual. b Camera lucida drawing of external mold of specimen CGS SZ 359, Vinice slope near Jince locality, outcrop behind the house of Baborsky´, Prˇ´ıbram–Jince Basin. Scale bar 1 mm
Dimensions Appendages
Theca Diameter of primary plates Diameter of secondary plates Proximal stem Distal stem
Bent—3.0 and 7.0 mm, Straight—minimum 8.0 mm Width—0.3–0.4 mm Height—3.7 mm Width—3.0 mm 0.6–1.2 mm 0.4–0.9 mm Height—1.2 mm Width—1.5 mm Height—5.0 mm Width—0.2–0.6 mm
Discussion: Although the only known specimen is quite small and crushed, it shows enough morphological features to be assigned to the family Dibrachicystidae without any doubt. The morphology of the two feeding appendages attached to the proximal part of theca, and the stem diversified into the proximal part composed by coneshaped plates and the distal part composed by cylindrical
columnals, are the same as in Dibrachicystis and Vizcainoia. Also the theca is composed by large primary (tessellate) plates surrounded by smaller secondary plates. However, the major difference between Dibrachicystis and Vizcainoia is in the morphology of feeding appendages. Presence of spine-like cover plates combined with the absence of secondary cover plates recalls the construction of feeding appendages in V. moncaiensis. The granulometry of embedding sediment excludes the possibility to prove the presence of external keel in uniserial elements of feeding appendages. Dibrachicystidae gen. et sp. indet. Fig. 4a–d v 1984 Acanthocystites sp. Fatka and Kordule, p. 300–301, pl. II, figs. 3, 4. v 2004 Eocrinoid sp. Fatka et al., p. 379. v p.p. 2004 Acanthocystites briareus Fatka et al., p. 379. Material and occurrence: Six isolated thecal plates collected from the Rejkovice ‘‘ve zˇluty´ch’’ locality (Figs. 1b, 2a).
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Fig. 4 Dibrachicystidae gen. et sp. indet. isolated thecal plates. a, b A large (primary tessellate) plate with radial ridges/grooves associated with several smaller (secondary) plates L 42234. c Large plate with radial grooves, internal mold. d Large plate with radial grooves, internal mold. a–c Paradoxides (Eccaparadoxides) pusillus Biozone, Skryje Member, Buchava Formation, old quarry called
Buchava, Skryje–Ty´rˇovice Basin. d Overlap of the Acadolenus snajdri and the Paradoxides (Eccaparadoxides) pusillus Trilobite Zones, Jince Formation, Rejkovice ‘‘ve zˇluty´ch’’ locality, Prˇ´ıbram– Jince Basin. L 42235. e, f Details of the feeding appendages SZ359. cp cover plate, pr primary ridge, sp spike, sr secondary ridge, ufp uniserial flooring plate. Scale bar 1 mm
About ten isolated thecal plates collected from middle levels of the Skryje Member, Buchava Formation in the Skryje–Ty´rˇovice Basin at the old quarry called Buchava (Figs. 1c, 2b).
Buchava (Fatka and Kordule 1992). These rare polygonal thecal plates with robust radial ribs showed a morphology which excluded their origination from predescribed edrioasteroids, cinctans, stylophorans, or from the eocrinoids Lichenoides and Luhocrinus. The restricted and poorly preserved material excluded ascertainment of the presence of elevations surrounding intersutural pores. Consequently, these plates were interpreted as calyx plates of eocrinoids and were provisionally classified as Acanthocystites sp. (see Fatka and Kordule 1984, 1992; Fatka et al. 2004). Recently collected new material supplemented the morphology of these isolated plates and made it possible to classify them as Dibrachicystidae gen. et sp. indet.
Description: Isolated thecal plates are polygonal with pleated margins and show 7 to 12 radial ridges on the external mold; these ridges are preserved as grooves on the internal mold. Some of ridges are developed across the plates (pr in Fig. 4c), while others do not reach the centrum of the plate (sr in Fig. 4d); these ridges are in agreement with Zamora and Smith (2012), called primary and secondary ridges, respectively.
Discussion
Age of Dibrachicystidae
Barrande (1887) and later authors collected echinoderm rests directly from the Paradoxides (Paradoxides) paradoxissimus gracilis Trilobite Zone and/or from the immediately underlying layers (e.g., Prokop 1962; Havlı´cˇek 1971). Since the early 1960s, diverse isolated echinoderm plates were ascertained outside the middle stratigraphical levels of the Jince Formation (Prokop 1960; Fatka and Kordule 1984, 1985; Fatka et al. 2004). Two small collections of echinoderm plates were gathered from the lower levels of the Paradoxides (Eccaparadoxides) pusillus Trilobite Zone in the surroundings of Rejkovice Village as well as at the old quarry called
The family Dibrachicystidae contains three species, namely Dibrachicystis purujoensis Zamora and Smith, 2012, Vizcainoia languedocianus (Ubaghs, 1987), and V. moncaiensis Zamora and Smith, 2012. V. languedocianus was originally described as Eocystites languedocianus by Ubaghs (1987) from the Lower Languedocian Solenopleuropsis (Solenopleuropsis) Zone of Montagne Noire (France). V. moncaiensis was established in the Middle Caesaraugustian Pardailhania multispinosa Zone at Purujosa, Section 6 in the Moncayo Natural Park, northernmost Iberian Chains, northern Spain (Zamora and Smith 2012).
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Family Dibrachicystidae from the ‘‘Middle’’ Cambrian of the Barrandian area
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Fig. 5 Inferred stratigraphical range of the family Dibrachicystidae. Correlation adopted after Gozalo et al. (2011) and Heuse et al. (2010)
One specimen of Dibrachicystis purujoensis was for the first time figured by Zamora (2010, pp. 507, 509, fig. 3c) as ‘‘a new group of blastozoans (‘‘eocystitids’’).’’ Articulated specimens of D. purujoensis were collected from the Lower Languedocian Solenopleuropsis thorali Zone at Purujosa, Section 3 in the Moncayo Natural Park, northernmost Iberian Chains, northern Spain. All known species of Dibrachicystidae have been established in the Iberian Chains of northern Spain and in Montagne Noire of France, i.e., in southwestern Europe belonging originally to the European peri-Gondwana. In the Barrandian area, all three outcrops with Dibrachicystidae contain also trilobite and other fauna which could be correlated with the interval between the latest unnamed stage 5 to the earliest Drumian of ‘‘Middle’’ ´ lvaro et al. 2004; Geyer et al. 2008). The Cambrian (A newly described occurrence of Dibrachicystidae in the Barrandian area is slightly older compared with the earlier established species known from southwestern Europe (Fig. 5).
Conclusions The new records of Vizcainoia and Dibrachicystidae gen. et sp. indet. from the Prˇ´ıbram–Jince and Skryje–Ty´rˇovice Basins represent a geographic and stratigraphic extension of the previously restricted occurrence. However, the distribution of all members of the family Dibrachicystidae is
still unequivocally restricted to early ‘‘Middle’’ Cambrian in southwestern and central Europe (=European periGondwana and/or West Gondwana sensu Vaughan and Pankhurst 2008). Acknowledgments We thank Samuel Zamora (Smithsonian Institution, Washington, USA) and Mike Reich (Georg-August University of Go¨ttingen, Germany) for their linguistic improvements and constructive comments on an earlier version. This study was supported by MSM 0021620855 (Material flow mechanisms in the upper spheres of the Earth), the Czech Science Foundation through project no. 205/09/ 1521 (Feeding strategies in Cambrian to Middle Ordovician of the Barrandian Region). This paper is a contribution to the International Geoscience Programme (IGCP) 591, ‘‘The Early to Middle Palaeozoic Revolution’’ and to the Agence Nationale de la Recherche, Programme Blanc SIMI 5–6 RALI.
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